--  @testpoint:opengauss关键字returned_sqlstate(非保留)，作为函数名
--关键字不带引号-成功
drop function if exists returned_sqlstate;
create function returned_sqlstate(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--清理环境
drop function returned_sqlstate;

--关键字带双引号-成功
drop function if exists "returned_sqlstate";
create function "returned_sqlstate"(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
drop function "returned_sqlstate";

--关键字带单引号-合理报错
drop function if exists 'returned_sqlstate';
create function 'returned_sqlstate'(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/

--关键字带反引号-合理报错
drop function if exists `returned_sqlstate`;
create function `returned_sqlstate`(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/